586 research outputs found
Antipyretic and analgesic activities of aqueous extract of Acacia nilotica root
This study was designed to investigate the scientific basis for the use of Acacia nilotica root extract for treatment of fever and pain in traditional medical practice. Anti-Pyretic study was carried out using BrewerĘĽs yeast suspension to induce pyrexia. The hot plate, tail immersion and acetic acid-induced writhing tests were the nociceptive models used for analgesic study. Anti-pyretic and analgesic activity of the extract was compared with acetaminophen that was used as control drug. Five groups comprising five animals per group were used for each study. Group 1 was administered 10 ml/kg body weight of distilled water, Group 2 was administered 150 mg/kg body weight of acetaminophen while groups 3, 4 and 5 were administered 100, 200 and 400 mg/kg body weight of extract respectively as single oral dose. The extract produced significant dose-dependent reduction in rectal temperature of rats at 200 and 400 mg/kg body weight. Significant analgesic activities were also observed in the hot plate, tail immersion and acetic acid induced writhing, after administration of 200 and 400 mg/kg b.w of extract which is comparable to the control drug, acetaminophen. The results from this study showed that aqueous extract of Acacia nilotica root at 200 and 400 mg/kg body weight possess significant antipyretic and analgesic activities. This provides scientific support for its traditional medical use in the treatment of fever and pain.Keywords: Antipyrexia, Analgesia, Acacia nilotica, BrewerĘĽs yeast
Effect of Light Intensities on Growth Performance of Tetrapleura tetraptera Seedlings Schum. (Thonn.)
The study assessed the effect of varying light intensities and optimum
percentage of sunlight favourable for raising Tetrapleura tetraptera
seedlings. The light intensity was measured through photometer. The
experiment was subjected to a control without wire mesh(T1) and three
other treatments (T2, T3 and T4) covered with different layers of black
wire mesh with 99.5%, 75%, 49.8% and 25% light intensities
respectively. Each of the treatments was replicated six times in a
completely randomized design. The plant height, leaf production and
stem diameter were all monitored for 12 weeks. Analysis of Variance
(ANOVA) was employed and the means separated using Least Significant
Difference (LSD). The results showed that the significance effect (P =
\u3b10.05) was only observed in the seedlings height of
Tetrapleuratetrapteraseedlings. However, the mean values obtained for
all the parameters considered revealed the treatment 1(i.e. 99.8% wire
mesh) was observed to be the best performing treatment. For the plant
height, mean value ranged between 13.09 cm and 16.8 cm, a range from
0.22cm to 0.28mm was recorded for stem girth while the mean values
between 22 and 27 were obtained for number of leaves among the
treatments. It may be concluded from the study, that light intensity of
100% i.e without interference should be used for the growth and
development as well as production of Tetrapleura tetraptera seedlings
in the nursery
Measurement-Induced Entanglement for Excitation Stored in Remote Atomic Ensembles
A critical requirement for diverse applications in Quantum Information
Science is the capability to disseminate quantum resources over complex quantum
networks. For example, the coherent distribution of entangled quantum states
together with quantum memory to store these states can enable scalable
architectures for quantum computation, communication, and metrology. As a
significant step toward such possibilities, here we report observations of
entanglement between two atomic ensembles located in distinct apparatuses on
different tables. Quantum interference in the detection of a photon emitted by
one of the samples projects the otherwise independent ensembles into an
entangled state with one joint excitation stored remotely in 10^5 atoms at each
site. After a programmable delay, we confirm entanglement by mapping the state
of the atoms to optical fields and by measuring mutual coherences and photon
statistics for these fields. We thereby determine a quantitative lower bound
for the entanglement of the joint state of the ensembles. Our observations
provide a new capability for the distribution and storage of entangled quantum
states, including for scalable quantum communication networks .Comment: 13 pages, 4 figures Submitted for publication on August 31 200
Photonic quantum technologies
The first quantum technology, which harnesses uniquely quantum mechanical
effects for its core operation, has arrived in the form of commercially
available quantum key distribution systems that achieve enhanced security by
encoding information in photons such that information gained by an eavesdropper
can be detected. Anticipated future quantum technologies include large-scale
secure networks, enhanced measurement and lithography, and quantum information
processors, promising exponentially greater computation power for particular
tasks. Photonics is destined for a central role in such technologies owing to
the need for high-speed transmission and the outstanding low-noise properties
of photons. These technologies may use single photons or quantum states of
bright laser beams, or both, and will undoubtably apply and drive
state-of-the-art developments in photonics
Von Bezold assimilation effect reverses in stereoscopic conditions
Lightness contrast and lightness assimilation are opposite phenomena: in contrast,
grey targets appear darker when bordering bright surfaces (inducers) rather than dark ones; in
assimilation, the opposite occurs. The question is: which visual process favours the occurrence
of one phenomenon over the other? Researchers provided three answers to this question. The
first asserts that both phenomena are caused by peripheral processes; the second attributes their
occurrence to central processes; and the third claims that contrast involves central processes,
whilst assimilation involves peripheral ones. To test these hypotheses, an experiment on an IT
system equipped with goggles for stereo vision was run. Observers were asked to evaluate the
lightness of a grey target, and two variables were systematically manipulated: (i) the apparent
distance of the inducers; and (ii) brightness of the inducers. The retinal stimulation was kept
constant throughout, so that the peripheral processes remained the same. The results show that
the lightness of the target depends on both variables. As the retinal stimulation was kept constant, we
conclude that central mechanisms are involved in both lightness contrast and lightness assimilation
Ion Trap in a Semiconductor Chip
The electromagnetic manipulation of isolated atoms has led to many advances
in physics, from laser cooling and Bose-Einstein condensation of cold gases to
the precise quantum control of individual atomic ion. Work on miniaturizing
electromagnetic traps to the micrometer scale promises even higher levels of
control and reliability. Compared with 'chip traps' for confining neutral
atoms, ion traps with similar dimensions and power dissipation offer much
higher confinement forces and allow unparalleled control at the single-atom
level. Moreover, ion microtraps are of great interest in the development of
miniature mass spectrometer arrays, compact atomic clocks, and most notably,
large scale quantum information processors. Here we report the operation of a
micrometer-scale ion trap, fabricated on a monolithic chip using semiconductor
micro-electromechanical systems (MEMS) technology. We confine, laser cool, and
measure heating of a single 111Cd+ ion in an integrated radiofrequency trap
etched from a doped gallium arsenide (GaAs) heterostructure.Comment: 4 pages, 4 figure
Dissipative and Non-dissipative Single-Qubit Channels: Dynamics and Geometry
Single-qubit channels are studied under two broad classes: amplitude damping
channels and generalized depolarizing channels. A canonical derivation of the
Kraus representation of the former, via the Choi isomorphism is presented for
the general case of a system's interaction with a squeezed thermal bath. This
isomorphism is also used to characterize the difference in the geometry and
rank of these channel classes. Under the isomorphism, the degree of decoherence
is quantified according to the mixedness or separability of the Choi matrix.
Whereas the latter channels form a 3-simplex, the former channels do not form a
convex set as seen from an ab initio perspective. Further, where the rank of
generalized depolarizing channels can be any positive integer upto 4, that of
amplitude damping ones is either 2 or 4. Various channel performance parameters
are used to bring out the different influences of temperature and squeezing in
dissipative channels. In particular, a noise range is identified where the
distinguishability of states improves inspite of increasing decoherence due to
environmental squeezing.Comment: 12 pages, 4 figure
Architecture for a large-scale ion-trap quantum computer
Among the numerous types of architecture being explored for quantum computers are systems utilizing ion traps, in which quantum bits (qubits) are formed from the electronic states of trapped ions and coupled through the Coulomb interaction. Although the elementary requirements for quantum computation have been demonstrated in this system, there exist theoretical and technical obstacles to scaling up the approach to large numbers of qubits. Therefore, recent efforts have been concentrated on using quantum communication to link a number of small ion-trap quantum systems. Developing the array-based approach, we show how to achieve massively parallel gate operation in a large-scale quantum computer, based on techniques already demonstrated for manipulating small quantum registers. The use of decoherence-free subspaces significantly reduces decoherence during ion transport, and removes the requirement of clock synchronization between the interaction regions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62880/1/nature00784.pd
Unraveling the Design Principle for Motif Organization in Signaling Networks
Cellular signaling networks display complex architecture. Defining the design principle of this architecture is crucial for our understanding of various biological processes. Using a mathematical model for three-node feed-forward loops, we identify that the organization of motifs in specific manner within the network serves as an important regulator of signal processing. Further, incorporating a systemic stochastic perturbation to the model we could propose a possible design principle, for higher-order organization of motifs into larger networks in order to achieve specific biological output. The design principle was then verified in a large, complex human cancer signaling network. Further analysis permitted us to classify signaling nodes of the network into robust and vulnerable nodes as a result of higher order motif organization. We show that distribution of these nodes within the network at strategic locations then provides for the range of features displayed by the signaling network
Organ transplantation from deceased donors with vaccine-induced thrombosis and thrombocytopenia
Vaccine-induced thrombosis and thrombocytopenia (VITT) may follow immunisation with the ChAdOx1 nCoV-19 vaccine against SARS-CoV-2. Autoantibodies to platelet factor 4 (PF4) may mediate VITT through antibody-dependent platelet activation, though the underlying etiology is uncertain. Anti-PF4 antibodies are also seen in heparin-induced thrombocytopenia, though most cases of VITT do not have prior heparin exposure. More than 20 million people in the United Kingdom (UK) have received the ChAdOx1 nCoV-19 vaccine
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